This patch is: Reviewed-by: Iago Toral Quiroga <itoral@xxxxxxxxxx>
Iago
El lun, 11-03-2024 a las 07:06 -0300, Maíra Canal escribió:
> Create a separate "tmpfs" kernel mount for V3D. This will allow us to
> move away from the shmemfs `shm_mnt` and gives the flexibility to do
> things like set our own mount options. Here, the interest is to use
> "huge=", which should allow us to enable the use of THP for our
> shmem-backed objects.
>
> Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
> ---
> drivers/gpu/drm/v3d/Makefile | 3 ++-
> drivers/gpu/drm/v3d/v3d_drv.h | 9 +++++++
> drivers/gpu/drm/v3d/v3d_gem.c | 3 +++
> drivers/gpu/drm/v3d/v3d_gemfs.c | 46
> +++++++++++++++++++++++++++++++++
> 4 files changed, 60 insertions(+), 1 deletion(-)
> create mode 100644 drivers/gpu/drm/v3d/v3d_gemfs.c
>
> diff --git a/drivers/gpu/drm/v3d/Makefile
> b/drivers/gpu/drm/v3d/Makefile
> index b7d673f1153b..fcf710926057 100644
> --- a/drivers/gpu/drm/v3d/Makefile
> +++ b/drivers/gpu/drm/v3d/Makefile
> @@ -13,7 +13,8 @@ v3d-y := \
> v3d_trace_points.o \
> v3d_sched.o \
> v3d_sysfs.o \
> - v3d_submit.o
> + v3d_submit.o \
> + v3d_gemfs.o
>
> v3d-$(CONFIG_DEBUG_FS) += v3d_debugfs.o
>
> diff --git a/drivers/gpu/drm/v3d/v3d_drv.h
> b/drivers/gpu/drm/v3d/v3d_drv.h
> index 1950c723dde1..d2ce8222771a 100644
> --- a/drivers/gpu/drm/v3d/v3d_drv.h
> +++ b/drivers/gpu/drm/v3d/v3d_drv.h
> @@ -119,6 +119,11 @@ struct v3d_dev {
> struct drm_mm mm;
> spinlock_t mm_lock;
>
> + /*
> + * tmpfs instance used for shmem backed objects
> + */
> + struct vfsmount *gemfs;
> +
> struct work_struct overflow_mem_work;
>
> struct v3d_bin_job *bin_job;
> @@ -519,6 +524,10 @@ void v3d_reset(struct v3d_dev *v3d);
> void v3d_invalidate_caches(struct v3d_dev *v3d);
> void v3d_clean_caches(struct v3d_dev *v3d);
>
> +/* v3d_gemfs.c */
> +void v3d_gemfs_init(struct v3d_dev *v3d);
> +void v3d_gemfs_fini(struct v3d_dev *v3d);
> +
> /* v3d_submit.c */
> void v3d_job_cleanup(struct v3d_job *job);
> void v3d_job_put(struct v3d_job *job);
> diff --git a/drivers/gpu/drm/v3d/v3d_gem.c
> b/drivers/gpu/drm/v3d/v3d_gem.c
> index 66f4b78a6b2e..faefbe497e8d 100644
> --- a/drivers/gpu/drm/v3d/v3d_gem.c
> +++ b/drivers/gpu/drm/v3d/v3d_gem.c
> @@ -287,6 +287,8 @@ v3d_gem_init(struct drm_device *dev)
> v3d_init_hw_state(v3d);
> v3d_mmu_set_page_table(v3d);
>
> + v3d_gemfs_init(v3d);
> +
> ret = v3d_sched_init(v3d);
> if (ret) {
> drm_mm_takedown(&v3d->mm);
> @@ -304,6 +306,7 @@ v3d_gem_destroy(struct drm_device *dev)
> struct v3d_dev *v3d = to_v3d_dev(dev);
>
> v3d_sched_fini(v3d);
> + v3d_gemfs_fini(v3d);
>
> /* Waiting for jobs to finish would need to be done before
> * unregistering V3D.
> diff --git a/drivers/gpu/drm/v3d/v3d_gemfs.c
> b/drivers/gpu/drm/v3d/v3d_gemfs.c
> new file mode 100644
> index 000000000000..8518b7da6f73
> --- /dev/null
> +++ b/drivers/gpu/drm/v3d/v3d_gemfs.c
> @@ -0,0 +1,46 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/* Copyright (C) 2024 Raspberry Pi */
> +
> +#include <linux/fs.h>
> +#include <linux/mount.h>
> +
> +#include "v3d_drv.h"
> +
> +void v3d_gemfs_init(struct v3d_dev *v3d)
> +{
> + char huge_opt[] = "huge=always";
> + struct file_system_type *type;
> + struct vfsmount *gemfs;
> +
> + /*
> + * By creating our own shmemfs mountpoint, we can pass in
> + * mount flags that better match our usecase. However, we
> + * only do so on platforms which benefit from it.
> + */
> + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
> + goto err;
> +
> + type = get_fs_type("tmpfs");
> + if (!type)
> + goto err;
> +
> + gemfs = vfs_kern_mount(type, SB_KERNMOUNT, type->name,
> huge_opt);
> + if (IS_ERR(gemfs))
> + goto err;
> +
> + v3d->gemfs = gemfs;
> + drm_info(&v3d->drm, "Using Transparent Hugepages\n");
> +
> + return;
> +
> +err:
> + v3d->gemfs = NULL;
> + drm_notice(&v3d->drm,
> + "Transparent Hugepage support is recommended for
> optimal performance on this platform!\n");
> +}
> +
> +void v3d_gemfs_fini(struct v3d_dev *v3d)
> +{
> + if (v3d->gemfs)
> + kern_unmount(v3d->gemfs);
> +}
> --
> 2.43.0
>
>
